diff --git a/gtk/a11y/gtkentryaccessible.c b/gtk/a11y/gtkentryaccessible.c
index f8aaabad87..3b8bcf3b23 100644
--- a/gtk/a11y/gtkentryaccessible.c
+++ b/gtk/a11y/gtkentryaccessible.c
@@ -961,7 +961,7 @@ gtk_entry_accessible_get_character_extents (AtkText      *text,
   pango_layout_index_to_pos (gtk_entry_get_layout (entry), index, &char_rect);
   pango_extents_to_pixels (&char_rect, NULL);
 
-  _gtk_widget_get_allocation (widget, &allocation);
+  gtk_widget_get_allocation (widget, &allocation);
 
   surface = gtk_widget_get_surface (widget);
   gdk_surface_get_origin (surface, &x_surface, &y_surface);
diff --git a/gtk/gtkcssboxesimplprivate.h b/gtk/gtkcssboxesimplprivate.h
index 0cab9750c5..98c1b71e0d 100644
--- a/gtk/gtkcssboxesimplprivate.h
+++ b/gtk/gtkcssboxesimplprivate.h
@@ -31,11 +31,13 @@ static inline void
 gtk_css_boxes_init (GtkCssBoxes *boxes,
                     GtkWidget   *widget)
 {
+  GtkWidgetPrivate *priv = widget->priv;
+
   gtk_css_boxes_init_content_box (boxes,
-                                  gtk_css_node_get_style (widget->priv->cssnode),
+                                  gtk_css_node_get_style (priv->cssnode),
                                   0, 0,
-                                  gtk_widget_get_width (widget),
-                                  gtk_widget_get_height (widget));
+                                  priv->width,
+                                  priv->height);
 }
 
 static inline void
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 67e0e19fbd..fb90d3c458 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -34,6 +34,7 @@
 #include "gtkbuildable.h"
 #include "gtkbuilderprivate.h"
 #include "gtkcontainerprivate.h"
+#include "gtkcssboxesprivate.h"
 #include "gtkcssfiltervalueprivate.h"
 #include "gtkcssfontvariationsvalueprivate.h"
 #include "gtkcssnumbervalueprivate.h"
@@ -4313,13 +4314,6 @@ gtk_widget_size_allocate (GtkWidget           *widget,
       real_allocation.height = MAX (1, real_allocation.height);
     }
 
-  /* Set the widget allocation to real_allocation now, pass the smaller allocation to the vfunc */
-  priv->transform.x = real_allocation.x;
-  priv->transform.y = real_allocation.y;
-  priv->width = real_allocation.width;
-  priv->height = real_allocation.height;
-  priv->baseline = baseline;
-
   if (!alloc_needed && !size_changed && !baseline_changed)
     {
       /* Still have to move the window... */
@@ -4342,6 +4336,9 @@ gtk_widget_size_allocate (GtkWidget           *widget,
   get_box_border (style, &border);
   get_box_padding (style, &padding);
 
+  priv->transform.x = real_allocation.x + margin.left + border.left + padding.left;
+  priv->transform.y = real_allocation.y + margin.top + border.top + padding.top;
+
   /* Since gtk_widget_measure does it for us, we can be sure here that
    * the given alloaction is large enough for the css margin/bordder/padding */
   real_allocation.x = 0;
@@ -4354,6 +4351,10 @@ gtk_widget_size_allocate (GtkWidget           *widget,
   if (baseline >= 0)
     baseline -= margin.top + border.top + padding.top;
 
+  priv->width = real_allocation.width;
+  priv->height = real_allocation.height;
+  priv->baseline = baseline;
+
   if (g_signal_has_handler_pending (widget, widget_signals[SIZE_ALLOCATE], 0, FALSE))
     g_signal_emit (widget, widget_signals[SIZE_ALLOCATE], 0,
                    real_allocation.width,
@@ -4457,23 +4458,8 @@ gtk_widget_get_origin_relative_to_parent (GtkWidget *widget,
                                           int       *origin_x,
                                           int       *origin_y)
 {
-  GtkWidgetPrivate *priv = gtk_widget_get_instance_private (widget);
-  GtkBorder margin, border, padding;
-  GtkCssStyle *style;
-
-  style = gtk_css_node_get_style (priv->cssnode);
-  get_box_margin (style, &margin);
-  get_box_border (style, &border);
-  get_box_padding (style, &padding);
-
-  /* allocation is relative to the parent's origin */
-  *origin_x = priv->transform.x;
-  *origin_y = priv->transform.y;
-
-  /* ... but points to the upper left, excluding widget margins
-   * but including all the css properties */
-  *origin_x += margin.left + border.left + padding.left;
-  *origin_y += margin.top + border.top + padding.top;
+  *origin_x = widget->priv->transform.x;
+  *origin_y = widget->priv->transform.y;
 }
 
 /**
@@ -11207,14 +11193,19 @@ gtk_widget_get_allocation (GtkWidget     *widget,
                            GtkAllocation *allocation)
 {
   GtkWidgetPrivate *priv = gtk_widget_get_instance_private (widget);
+  const graphene_rect_t *margin_rect;
+  GtkCssBoxes boxes;
 
   g_return_if_fail (GTK_IS_WIDGET (widget));
   g_return_if_fail (allocation != NULL);
 
-  allocation->x = priv->transform.x;
-  allocation->y = priv->transform.y;
-  allocation->width = priv->width;
-  allocation->height = priv->height;
+  gtk_css_boxes_init (&boxes, widget);
+  margin_rect = gtk_css_boxes_get_margin_rect (&boxes);
+
+  allocation->x = priv->transform.x + ceil (margin_rect->origin.x);
+  allocation->y = priv->transform.y + ceil (margin_rect->origin.y);
+  allocation->width = ceil (margin_rect->size.width);
+  allocation->height = ceil (margin_rect->size.height);
 }
 
 /**
@@ -11296,18 +11287,12 @@ gtk_widget_pick (GtkWidget *widget,
 
     case GTK_OVERFLOW_HIDDEN:
       {
-        GtkBorder margin, border, padding;
-        GtkCssStyle *style;
+        GtkCssBoxes boxes;
 
-        style = gtk_css_node_get_style (priv->cssnode);
-        get_box_margin (style, &margin);
-        get_box_border (style, &border);
-        get_box_padding (style, &padding);
+        gtk_css_boxes_init (&boxes, widget);
 
-        if (x < -padding.left ||
-            y < -padding.top  ||
-            x >= priv->width - margin.left - margin.right - border.left - border.right - padding.left ||
-            y >= priv->height - margin.top - margin.bottom - border.top - border.bottom - padding.top)
+        if (!graphene_rect_contains_point (gtk_css_boxes_get_padding_rect (&boxes),
+                                           &GRAPHENE_POINT_INIT (x, y)))
           return NULL;
       }
       break;
@@ -11339,39 +11324,26 @@ gtk_widget_compute_bounds (GtkWidget       *widget,
                            GtkWidget       *target,
                            graphene_rect_t *out_bounds)
 {
-  GtkWidgetPrivate *priv = gtk_widget_get_instance_private (widget);
-  GtkBorder margin, border, padding;
-  GtkCssStyle *style;
-  GtkAllocation alloc;
+  GtkCssBoxes boxes;
+  int x, y;
 
   g_return_val_if_fail (GTK_IS_WIDGET (widget), FALSE);
   g_return_val_if_fail (GTK_IS_WIDGET (target), FALSE);
   g_return_val_if_fail (out_bounds != NULL, FALSE);
 
-  style = gtk_css_node_get_style (priv->cssnode);
-  get_box_margin (style, &margin);
-  get_box_border (style, &border);
-  get_box_padding (style, &padding);
-
-  alloc.x = - (padding.left + border.left);
-  alloc.y = - (padding.top + border.top);
-  alloc.width = priv->width - margin.left - margin.right;
-  alloc.height = priv->height - margin.top - margin.bottom;
-
   if (!gtk_widget_translate_coordinates (widget,
                                          target,
-                                         alloc.x, alloc.y,
-                                         &alloc.x, &alloc.y))
+                                         0, 0,
+                                         &x, &y))
     {
       graphene_rect_init_from_rect (out_bounds, graphene_rect_zero ());
       return FALSE;
     }
 
-  graphene_rect_init (out_bounds,
-                      alloc.x,
-                      alloc.y,
-                      alloc.width,
-                      alloc.height);
+  gtk_css_boxes_init (&boxes, widget);
+  graphene_rect_offset_r (gtk_css_boxes_get_border_rect (&boxes),
+                          x, y,
+                          out_bounds);
 
   return TRUE;
 }
@@ -11387,11 +11359,13 @@ gtk_widget_compute_bounds (GtkWidget       *widget,
 int
 gtk_widget_get_allocated_width (GtkWidget *widget)
 {
-  GtkWidgetPrivate *priv = gtk_widget_get_instance_private (widget);
+  GtkCssBoxes boxes;
 
   g_return_val_if_fail (GTK_IS_WIDGET (widget), 0);
 
-  return priv->width;
+  gtk_css_boxes_init (&boxes, widget);
+
+  return gtk_css_boxes_get_margin_rect (&boxes)->size.width;
 }
 
 /**
@@ -11405,11 +11379,13 @@ gtk_widget_get_allocated_width (GtkWidget *widget)
 int
 gtk_widget_get_allocated_height (GtkWidget *widget)
 {
-  GtkWidgetPrivate *priv = gtk_widget_get_instance_private (widget);
+  GtkCssBoxes boxes;
 
   g_return_val_if_fail (GTK_IS_WIDGET (widget), 0);
 
-  return priv->height;
+  gtk_css_boxes_init (&boxes, widget);
+
+  return gtk_css_boxes_get_margin_rect (&boxes)->size.height;
 }
 
 /**
@@ -13028,35 +13004,23 @@ gtk_widget_reset_controllers (GtkWidget *widget)
 }
 
 static inline void
-gtk_widget_maybe_add_debug_render_nodes (GtkWidget             *widget,
-                                         GtkSnapshot           *snapshot)
+gtk_widget_maybe_add_debug_render_nodes (GtkWidget   *widget,
+                                         GtkSnapshot *snapshot)
 {
   GtkWidgetPrivate *priv = gtk_widget_get_instance_private (widget);
   GdkDisplay *display = _gtk_widget_get_display (widget);
-  GtkCssStyle *style;
-  GtkBorder margin, border, padding;
-
-  /* We should be offset to priv->allocation at this point */
 
   if (GTK_DISPLAY_DEBUG_CHECK (display, BASELINES))
     {
-      int baseline = gtk_widget_get_allocated_baseline (widget);
-
-      if (baseline != -1)
+      if (priv->baseline != -1)
         {
           GdkRGBA red = {1, 0, 0, 1};
           graphene_rect_t bounds;
 
-          style = gtk_css_node_get_style (priv->cssnode);
-          get_box_margin (style, &margin);
-          get_box_border (style, &border);
-          get_box_padding (style, &padding);
-
           /* Baselines are relative to the widget's origin,
            * and we are offset to the widget's allocation here */
           graphene_rect_init (&bounds,
-                              0,
-                              margin.top + border.top + padding.top + baseline,
+                              0, priv->baseline,
                               priv->width, 1);
           gtk_snapshot_append_color (snapshot,
                                      &red,
@@ -13102,7 +13066,7 @@ gtk_widget_create_render_node (GtkWidget   *widget,
 
   snapshot = gtk_snapshot_new_with_parent (parent_snapshot);
 
-  _gtk_widget_get_allocation (widget, &allocation);
+  gtk_widget_get_allocation (widget, &allocation);
   gtk_snapshot_push_debug (snapshot,
                            "RenderNode for %s %p @ %d x %d",
                            G_OBJECT_TYPE_NAME (widget), widget,
@@ -13741,20 +13705,10 @@ int
 gtk_widget_get_width (GtkWidget *widget)
 {
   GtkWidgetPrivate *priv = gtk_widget_get_instance_private (widget);
-  GtkBorder margin, border, padding;
-  GtkCssStyle *style;
 
   g_return_val_if_fail (GTK_IS_WIDGET (widget), 0);
 
-  style = gtk_css_node_get_style (priv->cssnode);
-  get_box_margin (style, &margin);
-  get_box_border (style, &border);
-  get_box_padding (style, &padding);
-
-  return priv->width -
-         margin.left  - margin.right -
-         border.left  - border.right -
-         padding.left - padding.right;
+  return priv->width;
 }
 
 /**
@@ -13771,18 +13725,8 @@ int
 gtk_widget_get_height (GtkWidget *widget)
 {
   GtkWidgetPrivate *priv = gtk_widget_get_instance_private (widget);
-  GtkBorder margin, border, padding;
-  GtkCssStyle *style;
 
   g_return_val_if_fail (GTK_IS_WIDGET (widget), 0);
 
-  style = gtk_css_node_get_style (priv->cssnode);
-  get_box_margin (style, &margin);
-  get_box_border (style, &border);
-  get_box_padding (style, &padding);
-
-  return priv->height -
-         margin.top  - margin.bottom -
-         border.top  - border.bottom -
-         padding.top - padding.bottom;
+  return priv->height;
 }
diff --git a/gtk/gtkwidgetprivate.h b/gtk/gtkwidgetprivate.h
index 0392c1bafb..35753b6736 100644
--- a/gtk/gtkwidgetprivate.h
+++ b/gtk/gtkwidgetprivate.h
@@ -460,18 +460,6 @@ _gtk_widget_get_surface (GtkWidget *widget)
   return widget->priv->surface;
 }
 
-static inline void
-_gtk_widget_get_allocation (GtkWidget     *widget,
-                            GtkAllocation *allocation)
-{
-  GtkWidgetPrivate *priv = widget->priv;
-
-  allocation->x = priv->transform.x;
-  allocation->y = priv->transform.y;
-  allocation->width = priv->width;
-  allocation->height = priv->height;
-}
-
 static inline GtkWidget *
 _gtk_widget_get_prev_sibling (GtkWidget *widget)
 {
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index abe113e758..ab5061d5f4 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -1728,7 +1728,7 @@ edge_under_coordinates (GtkWindow     *window,
       (priv->edge_constraints & constraints) != constraints)
     return FALSE;
 
-  _gtk_widget_get_allocation (GTK_WIDGET (window), &allocation);
+  gtk_widget_get_allocation (GTK_WIDGET (window), &allocation);
   context = _gtk_widget_get_style_context (GTK_WIDGET (window));
   gtk_style_context_save_to_node (context, priv->decoration_node);
 
@@ -5271,7 +5271,7 @@ gtk_window_move (GtkWindow *window,
     {
       GtkAllocation allocation;
 
-      _gtk_widget_get_allocation (widget, &allocation);
+      gtk_widget_get_allocation (widget, &allocation);
 
       /* we have now sent a request with this position
        * with currently-active constraints, so toggle flag.
@@ -6063,7 +6063,7 @@ popover_get_rect (GtkWindowPopover      *popover,
   gdouble min, max;
 
   gtk_widget_get_preferred_size (popover->widget, NULL, &req);
-  _gtk_widget_get_allocation (GTK_WIDGET (window), &win_alloc);
+  gtk_widget_get_allocation (GTK_WIDGET (window), &win_alloc);
 
   get_shadow_width (window, &win_border);
   win_alloc.x += win_border.left;
@@ -6449,7 +6449,7 @@ gtk_window_realize (GtkWidget *widget)
       g_return_if_fail (!_gtk_widget_get_realized (widget));
     }
 
-  _gtk_widget_get_allocation (widget, &allocation);
+  gtk_widget_get_allocation (widget, &allocation);
 
   if (priv->hardcoded_surface)
     {
@@ -6827,7 +6827,7 @@ gtk_window_configure (GtkWindow *window,
    * have been a queued resize from child widgets, and so we
    * need to reallocate our children in case *they* changed.
    */
-  _gtk_widget_get_allocation (widget, &allocation);
+  gtk_widget_get_allocation (widget, &allocation);
   if (priv->configure_request_count == 0 &&
       (allocation.width == width && allocation.height == height))
     {
@@ -7048,7 +7048,7 @@ get_active_region_type (GtkWindow *window, gint x, gint y)
       gtk_widget_get_visible (priv->title_box) &&
       gtk_widget_get_child_visible (priv->title_box))
     {
-      _gtk_widget_get_allocation (priv->title_box, &allocation);
+      gtk_widget_get_allocation (priv->title_box, &allocation);
       if (allocation.x <= x && allocation.x + allocation.width > x &&
           allocation.y <= y && allocation.y + allocation.height > y)
         return GTK_WINDOW_REGION_TITLE;
@@ -7428,7 +7428,7 @@ gtk_window_style_updated (GtkWidget *widget)
       GtkAllocation allocation;
       GtkBorder window_border;
 
-      _gtk_widget_get_allocation (widget, &allocation);
+      gtk_widget_get_allocation (widget, &allocation);
       get_shadow_width (window, &window_border);
 
       update_opaque_region (window, &window_border, &allocation);
@@ -7974,7 +7974,7 @@ gtk_window_compute_configure_request (GtkWindow    *window,
 
             gdk_surface_get_origin (surface, &ox, &oy);
 
-            _gtk_widget_get_allocation (parent_widget, &allocation);
+            gtk_widget_get_allocation (parent_widget, &allocation);
             x = ox + (allocation.width - w) / 2;
             y = oy + (allocation.height - h) / 2;